Diet of Corncrakes Crex crex and Prey Availability in Relation to Meadow Management

摘要: Land management intensification has caused declines in many grassland bird species. Corncrakes breed agriculturally managed meadows and are mainly threatened by nest loss during mowing operations, but may also be affected alternations habitat food availability. We analysed faecal samples to identify the diet composition of a river floodplain north-eastern Germany related abundance ground-dwelling invertebrates, sampled with pitfall traps, practice. The most frequent sources were beetle imagines (43%) which one third belonged Carabidae family, followed snails, larvae, spiders earthworms. Prey length was on average 11.2 ± 9.8 mm (±SD). Gastropoda species large beetles (>10 mm) consumed more often compared their availability at capture sites Corncrakes. Invertebrate peaked June decreased course breeding season. Total biomass, richness, particular numbers ground beetles, substantially higher unmanaged than mown or grazed preceding year. Highest invertebrate occurred first second year after abandonment, strongly afterwards similar level as under annual management. Our results suggest that rotational intervals two three years would beneficial for invertebrates. Under eutrophic conditions floodplains, undergo rapid succession quality deteriorates already subsequent cessation. Corncrake protection measures, like uncut refuge areas delayed dates, mitigate negative effects invertebrates enhance potential prey resources meadows.